Their party in crisis, Republicans' frustration with Donald Trump reached new heights on Wednesday as GOP leaders scrambled to persuade the presidential nominee to abandon divisive tactics that have led to sinking poll numbers and low morale.

Party chairman Reince Priebus appealed to the New York billionaire's adult children to help.

Priebus joined a handful of high-profile Trump allies in considering whether to confront the candidate directly following a series of startling stances and statements with Election Day quickly approaching. Trump has exposed deepening party divisions by refusing to endorse GOP House Speaker Paul Ryan's re-election and continuing to criticize the family of a slain U.S. soldier.

An official with direct knowledge of Priebus' thinking was granted anonymity to discuss internal strategy after one of the most tumultuous weeks of Trump's presidential campaign.

Yet the most powerful Republicans in Washington and New York's Trump Tower concede things will not change unless Trump wants them to.

"The candidate is in control of his campaign," campaign chairman Paul Manafort told the Fox News Network Wednesday afternoon. "And I'm in control of doing the things that he wants me to do in the campaign."

Priebus, a close friend of Ryan, is deeply irritated by Trump's recent actions and his unwillingness to accept guidance from senior advisers. The party chairman and the Trump confidants, as well as numerous GOP lawmakers, have been particularly irked by the candidate's repeated criticism of an American Muslim family whose son, a U.S. Army captain, was killed in Iraq.

"I would say in the last couple of weeks, he has been remarkably underperforming and we'll see whether or not he can take a deep breath and learn these lessons," said former House Speaker Newt Gingrich on Fox Business News.

Gingrich may join Priebus and another Trump ally, former New York City Mayor Rudy Giuliani, in specifically urging Trump to adjust his approach, according to the Republican official.

Trump on Wednesday dismissed suggestions that the GOP frustration was hurting his campaign.

He wrote on Twitter: "There is great unity in my campaign, perhaps greater than ever before. I want to thank everyone for your tremendous support. Beat Crooked H!" — a reference to Democratic nominee Hillary Clinton.

Yet Trump's vice presidential nominee, Indiana Gov. Mike Pence, appeared to break with him later in the day during a phone interview with Fox.

Pence said he spoke with Trump Wednesday morning "about my support for Paul Ryan and our longtime friendship. He strongly encouraged me to endorse Paul Ryan in next Tuesday's primary. And I'm pleased to do it."

Trump stunned Republicans by telling The Washington Post in an interview Tuesday that he wasn't ready to endorse Ryan, who faces a primary contest in Wisconsin next week. Ryan has backed Trump despite deep differences on policy and temperament, and has encouraged other Republicans to unite behind the party's nominee.

Trump's latest comments came on the heels of his criticism of Khizr and Ghazala Khan, whose son was killed in Iraq in 2004. Trump has said he himself was "viciously attacked" by the Khans, who appeared at last week's Democratic convention and challenged the Republican's fitness to be commander in chief.

The turbulent week, backed by sinking poll numbers, has led to low morale within Trump's small campaign team. After months of Trump promising to adopt a more presidential tone, Republicans are beginning to lose hope of a pivot for the general election.

Former Trump adviser Barry Bennett acknowledged signs of poor morale among the campaign staff he maintains contact with, but he also said it would be silly dismiss Trump's chances with three months before Election Day.

"This would be the end of any other Republican candidate in the history of the country. And he's only 5 or 6 points behind," Bennett said.

Indeed, Trump on Wednesday reported raising $80 million in July for his campaign and the Republican Party.

The numbers mark a significant upswing since May, when he was badly outraised by Democratic rival Clinton. He began August with $37 million in his campaign account.

Clinton raised $63 million in July for her campaign, as well as $26 million for the Democratic National Committee and state parties, bringing her total monthly fundraising to about $90 million.

Trump's $80 million includes about $64 million raised through online and direct mail appeals, the campaign said, evidence that Trump is leaning on small donors to finance the bulk of his presidential run.

He's also continuing to invest his own money, contributing $2 million last month.

Manafort dismissed reports of a so-called intervention by Priebus, Gingrich and Giuliani.

"The campaign's focused and the campaign is moving forward in a positive way," Manafort told Fox. "The only need we have for an intervention is maybe with some media types who keep saying things that aren't true."